Definition: In a playoff series, one team (usually the team with the better overall record) is scheduled to open the series at home and play an extra game at home if necessary. Teams tend to win more at home than on the road, so this is perceived to be an advantage.
In a typical best-of-seven series, the team with home ice advantage will play games one and two at home and games three and four on the road. If the series continues beyond that point, the advantaged team will play games five and seven at home.
When the visitng team wins one of the first two games, it is often said to have "stolen" home ice advantage. That team is now in a position to win the series by winning all their home games, without needing another road victory.
